The widespread distribution in the environment of cyclopenta(cd) pyrene (CPP) and its carcinogenic activity in preliminary studies indicate the need for thorough investigation of the biological properties of this hydrocarbon. This proposal is concerned with the synthesis, carcinogenicity, mutagenicity, metabolism and binding studies of CPP. 3,4-Dihydroxycyclopenta(cd)pyrene (DCPP), a constituent of coal tar pitch, will also be an integral part of this study. A simple and efficient synthesis of CPP is proposed, and will also be applicable to preparation of a 14C analog. DCPP and some of the major potential metabolites will be synthesized from CPP. The carcinogenic effect of CPP will be proven definitively by repeated application and initiation-promotion in mouse skin. The carcinogenicity of DCPP will also be tested. The biological effect of the two hydrocarbons will be compared to that of the potential carcinogenic metabolite of CPP, CPP-3,4-oxide and of the environmental carcinogen benzo(a)pyrene (BP). In addition, the carcinogenic effect of CPP and BP will be investigated at relative ratios of the hydrocarbons in various carbon blacks. The metabolism of (14C)CPP and (14C)DCLPP will be studied with mouse skin homogenates and microsomes of induced and uninduced mice. Mutagenicity of synthesized and identified metabolites of CPP and DCPP will be tested in Salmonella typhimurium. The comparative binding level of 14C-labeled CPP, DCPP and BP to mouse skin DNA will also be an integral part of our studies. Furthermore, analysis and comparison of nucleic acid base-CPP adducts will be conducted. The adducts will be obtained from a. DNA incubated with CPP-3,4 oxide and hydrolyzed to monomers, b. DNA incubated with CPP and liver microsomes and hydrolyzed and c. hydrolyzed DNA from mouse skin treated with CPP. The combined studies of metabolism, mutagenicity, carcinogenicity and binding of CPP should cast light on its mechanism of activation. These collected data, along with epidemiological and analytical data, will allow a more precise assessment of the environmental and occupational health hazard of CPP.